1. Field of Invention
This invention relates to the method of producing liquid disperse systems with the aid of hydrodynamic cavitation. This method may find application in chemical, petroleum, food, cosmetic, pharmaceutical and other branches of industry.
2. Description of the Related Art
At the present time, there are many known methods of producing liquid disperse systems, in particular, suspensions and emulsions, using the effect of hydrodynamic cavitation. In these methods, the emulsification and dispersion processes go on as a result of cavitation influences purposely created in the processing flow by the hydrodynamic course as a result of the passage of the flow through a localized constriction of the flow. The mixing, emulsifying and dispersing influences of hydrodynamic cavitation occur as a result of a great number of powerful influences on the processed components under the collapsing cavitation bubbles.
Known is the issued patent entitled Process and apparatus for obtaining the emulsification of nonmiscible liquids, U.S. Pat. No. 3,937,445 issued Feb. 10, 1976 to V. Agosta, comprising a decrease in the static pressure in the liquid as a result of the passage of it through a constricted Venturi channel, to the pressure of saturated vapors of the liquid and the creation of oscillating cavitation bubbles.
The described method does not provide a high effectiveness of emulsification, in so far as the intensity of the rise of pulsating field of cavitating bubbles is low. The energy which is emitted by the pulsations of a cavitation bubble is always lower than the energy emitted by the collapse of a cavitation bubble. Furthermore, in this case method, uncontrolled cavitation is used that results in the bubbles being distributed in the large volume of the liquid medium. This leads to a decrease in the level of energy dissipation in the mass unit of the medium and does not allow production of thin emulsions.
In another known patent entitled Method of obtaining free disperse system and device for effecting same, U.S. Pat. No. 5,492,654 issued Feb. 20, 1996 to O. Kozjuk et al, which comprises the passage of hydrodynamic flow through a flow-through channel with a baffle body positioned inside of it providing a localized construction of the flow and creation of a cavitation field downstream of it.
Such a method is sufficiently effective for emulsification processes. However, the use of it for homogenization processes when rather finely dispersed emulsions are required during a single pass of components through the device is significantly difficult, and at times not possible. This is associated with the fact that a significant part of the flow energy goes to the generation of the primary cavity, which thereafter tears away from the baffle body and breaks up on the bubbles. The bubbles collapse in the primary cavity disintegration zone where the static pressure in the surrounding liquid appears to be low. At the same time, the static pressure of the surrounding liquid bubbles appears as the main parameter which determines the level of energy emitted during collapse of cavitation bubble. The higher the magnitude of the static pressure, the better the result of cavitation dispersion.
Thus, there continues to exist a requirement for a method which may lead to improved emulsification, dispersion, and homogenization in a more effective way.
The present invention involving the method of producing liquid disperse systems allows creation of optimal regimes of cavitation dispersions as a result of maintenance of the most effective limits of the main parameters of the collapsing bubbles cavitation field. These parameters are related to the sizes of the bubbles, their concentration in the flow and the static pressure in the surrounding liquid bubbles at the moment of their collapse. Given these parameters, it is possible to create controlled cavitation, possessing the most effective technological regimes for dispersion.
The present invention contemplates a new and improved apparatus and method for producing liquid disperse systems with the aid of hydrodynamic cavitation which is simple in design, effective in use, and overcomes the foregoing difficulties and others while providing better and more advantageous overall results.